Linear Bearing LMK12LUU 12mm Square Flange Bushing The Linear Bearing LMK12LUU 12mm Square Flange Bushing is a low-cost linear motion system which equips with the cylindrical shaft. The working load of such bearings is small due to the point contact of the ball and the shaft. The balls can rotate with minimal frictional resistance, thus obtaining high-precision smooth movement. The Bearings gives you very precise, safe and reliable linear motion system. Such linear motion bearings are mostly used in 3D printers and CNC(Computer Numerical Control) machines. Widely used in home appliances, industrial, low noise and high-speed electric motors, construction machinery, automotive components, pumps, and machinery. check out : Linear Bearing LMK12UU 12mm Rod Square Flange Linear Bearing for 3D Printer Applications Replacement of parts of the 3D printer rail unit. Replacement of common machine tool guideway components. Laser (engraving machine) rail set-up and parts replacement Construction and replacement of small planning machine tables, carriers, rails and parts.